Permutation test: Difference between revisions

</pre>

=={{header|Rust}}==

<lang rust>

fn main() {

let treatment = vec![85, 88, 75, 66, 25, 29, 83, 39, 97];

let control = vec![68, 41, 10, 49, 16, 65, 32, 92, 28, 98];

let mut data_set = control.clone();

data_set.extend_from_slice(&treatment);

let greater = combinations(treatment.iter().sum(), treatment.len() as i64, &data_set) as f64;

let lesser = combinations(control.iter().sum(), control.len() as i64, &data_set) as f64;

let total = binomial(data_set.len() as i64, treatment.len() as i64) as f64;

println!("<= : {}%", (lesser / total * 100.0));

println!(" > : {}%", (greater / total * 100.0));

}

fn factorial(x: i64) -> i64 {

let mut product = 1;

for a in 1..(x + 1) {

product *= a;

}

product

}

fn binomial(n: i64, k: i64) -> i64 {

let numerator = factorial(n);

let denominator = factorial(k) * factorial(n - k);

numerator / denominator

}

fn combinations(total: i64, number: i64, data: &[i64]) -> i64 {

if total < 0 {

return binomial(data.len() as i64, number);

}

if number == 0 {

return 0;

}

if number > data.len() as i64 {

return 0;

}

if number == data.len() as i64 {

if total < data.iter().sum() {

return 1;

} else {

return 0;

}

}

let tail = &data[1..];

combinations(total - data[0], number - 1, &tail) + combinations(total, number, &tail)

}

</lang>

{{out}}

<pre>

<= : 86.8583428954946%

> : 12.80283184307952%